Maximum noble-metal efficiency in catalytic materials: atomically dispersed surface platinum

Area of Science:

• Materials Science
• Catalysis
• Surface Chemistry

Background:

• Platinum is a versatile catalyst but its scarcity and high cost limit applications.
• Conventional catalysts utilize only a small fraction of platinum, primarily surface atoms.
• Maximizing noble-metal efficiency requires atomically dispersed platinum within the outermost surface layer.

Purpose of the Study:

• To identify stable anchoring sites for atomically dispersed platinum on catalyst surfaces.
• To understand the mechanism preventing platinum sintering and bulk diffusion.
• To confirm the existence and catalytic relevance of these sites in real-world applications.

Main Methods:

• Density Functional Theory (DFT) calculations to identify stable platinum binding sites.
• Experimental validation using model catalysts.
• Characterization of real platinum-ceria (Pt-CeO2) nanocomposites.

Main Results:

• DFT identified a specific ceria "nanopocket" structure that strongly binds platinum ions (Pt2+).
• This strong binding prevents platinum atom sintering and diffusion into the bulk.
• Experimental studies confirmed the stability of platinum in these nanopockets on model and real catalysts.

Conclusions:

• Ceria nanopockets provide highly stable anchoring sites for atomically dispersed platinum.
• This strategy maximizes platinum utilization and efficiency in catalysis.
• The findings are directly applicable to improving fuel cell technology and other catalytic processes.